Sorption-enhanced steam reforming of propane using bifunctional Ni/CaO, Ni/CaO-CaZrO3, and Ni/CaO-Ca2SiO4 catalysts

In this study, the performance of bifunctional catalysts of Ni over CaO, CaO-CaZrO3 and CaO-Ca2SiO4 was evaluated in CO2 capture and sorption-enhanced steam propane reforming cycles. Ni/CaO, Ni/CaO-CaZrO3, and Ni/CaO-Ca2SiO4 catalysts/sorbent were synthesized by sol-gel process. X-ray diffraction (XRD) results showed the formation of CaZrO3 and Ca2SiO4 in the catalysts. The thermal stability performance of the samples was evaluated in CO2 capture and sorption-enhanced steam propane reforming cycles. Both tests confirmed a significant improvement of the performance during both CO2 capture and steam propane reforming with the addition of Zr and Si. This effect can be attributed to the minimization of CaO sintering due to the higher thermal stability added by the formation of CaZrO3 and Ca2SiO4. In addition, Ni/CaO-CaZrO3 sample presented the highest stability during sorption-enhanced steam propane reforming cycles, with pre-breakthrough time close to 50 min and H2 yields over 90 vol.% in the pre-breakthrough period and close to 71% in the post-breakthrough, in all reaction cycles. Therefore, the results showed that the formation of the mixed oxides CaZrO3 and Ca2SiO4 improved the thermal stability of the catalysts, which can be good materials for sorption-enhanced steam propane reforming process.